dt-bindings: input: awinic,aw86927: Add Awinic AW86938

Add bindings for the Awinic AW86938 haptic chip which can be found in
smartphones. These two chips require a similar devicetree configuration,
but have a register layout that's not 100% compatible.
Still, because chip model is fully detectable via ID register, these
chips can be documnented in the same file.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Griffin Kroah-Hartman <griffin.kroah@fairphone.com>
Link: https://patch.msgid.link/20260302-aw86938-driver-v4-2-92c865df9cca@fairphone.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>